This invention relates generally to cooling systems for internal combustion engines and, more particularly, to a novel arrangement of heat exchangers which eliminates the need for a conventional fan and radiator, thereby affording a substantial degree of flexibility in the design of a vehicle which uses the internal combustion engine as its motive power source.
Cooling systems for internal combustion engines used as the motive power source for automobiles and other such vehicles typically employ a liquid coolant, such as a water and ethylene glycol mixture, which is circulated through the engine block. Circulation of the liquid coolant is achieved using a liquid coolant or water pump typically driven by a belt from a crankshaft pulley. Conventionally, a multi-bladed fan is bolted to the water pump pulley, and this fan is used to draw air through the core of a radiator through which the liquid coolant circulates. In this way, the liquid coolant which has been heated in the engine block is cooled before recirculation to the engine block.
The conventional cooling system, while quite effective and serviceable, has certain disadvantages. These relate to the cooperative relationship and proximate placement of the radiator and fan. The radiator represents a certain amount of weight and bulk volume which must be accommodated in the engine compartment of the automobile. With the advent of the energy crisis, considerable effort is now being devoted to designing and producing smaller, more fuel efficient automobiles. With a reduction in size of the automobile, weight distribution and volume allocation become significant design factors. The fan itself represents a source of lost energy. This, of course, has been recognized by others who have provided such devices as clutches to disengage the fan when the automobile is moving at a substantial velocity, thereby producing a sufficient airflow through the radiator core without the aid of the fan. Nevertheless, the fan is required for low-speed operation, such as city driving, which is the most inefficient operation of the vehicle.